An Infection Model for SARS-CoV-2 Using Rat Transplanted with hiPSC-Airway Epithelial Cells.

Investigating the infection mechanism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the airway epithelium and developing effective defense strategies against infection are important. To achieve this, establishing appropriate infection models is crucial. Therefore, various in vitro models, such as cell lines and primary cultures, and in vivo models involving animals that exhibit SARS-CoV-2 infection and genetically humanized animals have been used as animal models. However, no animal model has been established that allows infection experiments with human cells under the physiological environment of airway epithelia. Therefore, we aimed to establish a novel animal model that enables infection experiments using human cells. Human induced pluripotent stem cell-derived airway epithelial cell-transplanted nude rats (hiPSC-AEC rats) were used, and infection studies were performed by spraying lentiviral pseudoviruses containing SARS-CoV-2 spike protein and the GFP gene on the tracheae. After infection, immunohistochemical analyses revealed the existence of GFP-positive-infected transplanted cells in the epithelial and submucosal layers. In this study, a SARS-CoV-2 infection animal model including human cells was established mimicking infection through respiration, and we demonstrated that the hiPSC-AEC rat could be used as an animal model for basic research and the development of therapeutic methods for human-specific respiratory infectious diseases.

Non-linear association between the time required to reaching temperature targets and the neurological outcome in patients undergoing targeted temperature management after out-of-hospital cardiac arrest: Observational multicentre cohort study.

Purpose: We evaluated associations between outcomes and time to achieving temperature targets during targeted temperature management of out-of-hospital cardiac arrest. Methods: Using Comprehensive Registry of Intensive Care for out-of-hospital cardiac arrest Survival (CRITICAL) study, we enrolled all patients transported to participating hospitals from 1 July 2012 through 31 December 2017 aged ≥ 18 years with out-of-hospital cardiac arrest of cardiac aetiology and who received targeted temperature management in Osaka, Japan. Primary outcome was Cerebral Performance Category scale of 1 or 2 one month after cardiac arrest, designated as "one-month favourable neurological outcome". Non-linear multivariable logistic regression analyses assessed the primary outcome based on time to reaching temperature targets. In patients subdivided into quintiles based on time to achieving temperature targets, multivariable logistic regression calculated adjusted odds ratios and 95% confidence intervals. Results: We analysed 473 patients. In non-linear multivariable logistic regression analysis, p value for non-linearity was < 0.01. In the first quintile (< 26.7 minutes), second quintile (26.8-89.9 minutes), third quintile (90.0-175.1 minutes), fourth quintile (175.2-352.1 minutes), and fifth quintile (≥ 352.2 minutes), one-month favourable neurological outcome was 32.6% (31/95), 40.0% (36/90), 53.5% (53/99), 57.4% (54/94), and 37.9% (36/95), respectively. Adjusted odds ratios with 95% confidence intervals for one-month favourable neurological outcome in the first, second, third, and fifth quintiles compared with the fourth quintile were 0.38 (0.20 to 0.72), 0.43 (0.23 to 0.81), 0.77 (0.41 to 1.44), and 0.46 (0.25 to 0.87), respectively. Conclusion: Non-linear multivariable logistic regression analysis could clearly describe the association between neurological outcome in patients with out-of-hospital cardiac arrest and the time from the introduction of targeted temperature management to reaching the temperature targets.

Clinical phenotypes of nontuberculous mycobacterial disease by cluster analysis based on pulmonary function.

BACKGROUND: Nontuberculous mycobacterial pulmonary disease (NTM-PD) often exhibits pulmonary function impairment, such as obstructive or restrictive pattern, with variation among patients according to the damaged lesions in the lung. METHODS: Patients with NTM-PD were consecutively enrolled between September 2019 and December 2020 at the Respiratory Infection Clinic of our hospital. Patients' data were comprehensively collected through laboratory examinations, PFT, chest computed tomography, and questionnaires for the assessment of subjective symptoms and health-related quality of life (HRQOL). Hierarchical cluster analysis was performed using PFT parameters to compare the clinical findings among clusters. RESULTS: Data of 104 patients were analyzed and classified into four clusters. The restrictive pattern with decreased forced expiratory volume in 1 s (FEV1) group showed high serum C-reactive protein and low albumin levels, severe radiological findings, and low HRQOL. In the restrictive pattern with preserved FEV1 group, HRQOL was as low as that in the restrictive pattern with decreased FEV1 group, and bacterial exacerbation was observed relatively frequently. HRQOL in the obstructive impairment group was maintained in comparison with that in the normal group. CONCLUSION: NTM-PD phenotypes were identified using cluster analysis based on PFT. Two different severe phenotypes were also observed. In the early stages of NTM-PD, PFT may be useful in recognizing disease progression.

Changes in the Proportion of Each Cell Type After hiPSC-Derived Airway Epithelia Transplantation.

No radical treatment is available for the regeneration of dysfunction and defects in airway epithelia. Artificial tracheae made of polypropylene and collagen sponge were used in clinical studies to reconstitute tracheae after resection. For early epithelialization of the luminal surface of the artificial trachea, a model was established, that is, an artificial trachea covered with human-induced pluripotent stem cell-derived airway epithelial cells (hiPSC-AECs) was transplanted into a tracheal defect in an immunodeficient rat. Unlike the cell types of hiPSC-derived cells that are currently used in clinical studies, AECs maintain tissues by proliferation and differentiation of basal cells into various cell types that constitute AECs constantly. Therefore, post-transplantation, the proportion of each cell type, such as ciliated and goblet cells, may change; however, no studies have examined this possibility. In this study, using our hiPSC-AEC-transplanted rat model, we investigated changes in the proportion of each cell type in hiPSC-AECs pre-transplantation and post-transplantation. As a result, the proportion of each cell type changed post-transplantation. The proportion of ciliated, basal, and club cells increased, and the proportion of goblet cells decreased post-transplantation. In addition, the proportion of each cell type in engrafted hiPSC-AECs is more similar to the proportion of each cell type in normal proximal airway tissue than the proportion of each cell type pre-transplantation. The results of this study are useful for the development of therapeutic techniques using hiPSC-AEC transplantation.

Comparative Study of Immunodeficient Rat Strains in Engraftment of Human-Induced Pluripotent Stem Cell-Derived Airway Epithelia.

The airway epithelia (AE) play a role in the clearance of foreign substances through ciliary motility and mucus secreted. We developed an artificial trachea that is made of collagen sponges and polypropylene mesh for the regeneration of the tracheal defect, and it was used for a clinical study. Then, a model in which the luminal surface of an artificial trachea was covered with a human-induced pluripotent stem cell-derived AE (hiPSC-AE) was transplanted into the tracheal defect of nude rats to promote epithelialization. In the future, this model was expected to be applied to research on infectious diseases and drug discovery as a trachea-humanized rat model. However, at present, sufficient engraftment has not been achieved to evaluate functional recovery in transplanted cells. Therefore, this study focused on immunosuppression in recipient rats. Nude rats lack T cell function and are widely used for transplantation experiments; however, more severe immunosuppressed recipients are preferred for xenotransplantation. Several strains of immunodeficient rats were created as rats that exhibit more severe immunodeficiency until now. In this study, to establish a trachea-humanized rat model in which human AE function can be analyzed to improve engraftment efficiency, engraftment efficiency in nude rats and X-linked severe combined immunodeficiency (X-SCID) rats following hiPSC-AE transplantation was compared. In the analysis of the proportion of engrafted cells in total cells at the graft site, the engraftment efficiency of epithelial cells tended to be high in X-SCID rats, although no statistical difference was found between the two groups, whereas the engraftment efficiency of mesenchymal cells was higher in X-SCID rats. Furthermore, the number of immune cells that accumulated in the grafts showed that a pan T cell marker, that is, CD3-positive cells, did not differ between the two strains; however, CD45-positive cells and major histocompatibility complex (MHC) class II-positive cells significantly decreased in X-SCID rats. These results indicate that X-SCID rats are more useful for the transplantation of hiPSC-AE into the tracheae to generate trachea-humanized rat models.

Concurrent trastuzumab deruxtecan-induced interstitial lung disease and COVID-19 in the treatment of advanced breast cancer.

Patients with cancer are at an increased risk of developing coronavirus disease 2019 (COVID-19) infection. Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate (ADC) against epidermal growth factor receptor 2 (HER2)-positive cancer, known to cause drug-induced interstitial lung disease (DILD), including drug-induced pneumonitis. A 60-year-old woman with breast cancer developed a fever during treatment with T-DXd and was diagnosed with COVID-19. The fever persisted for approximately 3 weeks, and chest computed tomography showed multiple consolidations with bilateral peripheral predominance. Since the clinical course was atypical for COVID-19 due to the long duration of the fever and the CT pattern was frequently seen in T-DXd-induced ILD, the patient was diagnosed with T-DXd-induced ILD, following which, prednisolone was started, leading to improvement in the symptoms and fading of shadows. Even in patients suspected of COVID-19 pneumonia, physicians should consider the possibility of DILD, particularly in patients undergoing cancer treatment.

Impact of methotrexate on humoral and cellular immune responses to SARS-CoV-2 mRNA vaccine in patients with rheumatoid arthritis.

The aim of this study was to longitudinally evaluate the undetermined impact of methotrexate (MTX) on the cumulative immunogenicity elicited by three doses of SARS-CoV-2 mRNA vaccination in patients with rheumatoid arthritis (RA). We prospectively evaluated vaccine-induced immune responses following the first dose, 1 and 6 months after the second dose, and 1 month after the third dose of BNT162b2 or mRNA-1273 in 144 SARS-CoV-2 naïve participants (70 patients with RA, 29 disease controls without immunosuppressive conditions, and 45 healthy controls). Humoral immune responses were assessed by quantifying anti-spike IgG antibody titers and the capacity of circulating antibodies to neutralize the ancestral SARS-CoV-2 strain and the Alpha, Delta, and Omicron variants. Vaccine-induced T-cell responses were measured using an interferon-gamma release assay. At 1 and 6 months after the second dose, anti-spike titers were highest in healthy controls, followed by disease controls and patients with RA. Multivariate analyses revealed that MTX treatment was significantly associated with a decrease in anti-spike titers, neutralizing activity, and SARS-CoV-2-specific interferon-gamma levels. Furthermore, MTX dose per body weight was negatively correlated with these two indices of humoral immune response. The third vaccine dose boosted anti-spike titers, especially in patients receiving MTX, while sera from these patients neutralized the Omicron variant far less robustly than those from healthy controls. In conclusion, MTX attenuated immunogenicity following two doses of SARS-CoV-2 mRNA vaccine in patients with RA, particularly resulting in dose-dependent suppression of the humoral immune response. Furthermore, MTX deteriorated the neutralizing activity against the Omicron variant, even after the third immunization.

Laryngeal Cartilage Regeneration of Nude Rats by Transplantation of Mesenchymal Stem Cells Derived from Human-Induced Pluripotent Stem Cells.

Previous studies transplanted human-induced pluripotent stem cells (hiPSCs)-derived mesenchymal stem cells (iMSCs) into thyroid cartilage defect of X-liked severe combined immunodeficiency (X-SCID) rats and confirmed transplanted cell survival and cartilage regeneration. Thus, this study aimed to investigate the contribution of iMSC transplantation to thyroid cartilage regeneration of nude rats. iMSCs were induced from hiPSCs via a neural crest cell lineage. Then, clumps formed from an iMSC/extracellular matrix complex were transplanted into thyroid cartilage defects in nude rats. The larynx was removed and histological and immunohistochemical analyses were performed 4 or 8 weeks after the transplantation. Human nuclear antigen (HNA)-positive cells were observed in 11 of 12 (91.7%) rats, which indicated that transplanted iMSCs survived in thyroid cartilage defects in nude rats. HNA-positive cells co-expressed SOX9, and type II collagen was identified around HNA-positive cells in 8 of 12 rats (66.7%), which indicated cartilage-like regeneration. Cartilage-like regeneration in nude rats in this study was comparable to the previous report on X-SCID rats (HNA-positive cells were observed in all 14 rats and cartilage-like regeneration was observed in 10 of 14 rats). This result suggests that nude rats could be an alternative to X-SCID rats in thyroid cartilage regeneration experiments using iMSCs, and this nude rat cartilage transplantation model may develop cartilage regeneration research concerning fewer problems such as infection due to immunosuppression.

Physiologic 18F-FDG muscle uptake in severe COPD: Implications for accurate lung cancer staging.

Recognizing physiologic 18F-fluorodeoxyglucose (FDG) uptake in severe COPD is crucial to avoid mistaking it for lung cancer metastasis. Correlating 18F-FDG avid lesions with co-registered computed tomography is essential for accurate lung cancer staging and preventing unnecessary interventions.

Transient asymptomatic pulmonary opacities in a patient with MET exon 14 skipping non-small cell lung cancer: A case report.

Mesenchymal epithelial transition factor receptor (MET) tyrosine kinase inhibitors (MET-TKIs) have been approved for the treatment of non-small cell lung cancers with MET exon 14 skipping mutations. Transient asymptomatic pulmonary opacities (TAPOs) associated with epidermal growth factor receptor (EGFR)-TKIs have been reported. Here, we report a case wherein ground-glass opacities (GGOs) appeared during the course of treatment with tepotinib, a MET-TKI, but spontaneously resolved with drug withdrawal, after which treatment was resumed with a reduced dose. Although there have been no reports of TAPOs with MET-TKIs, the clinical and imaging findings of this case were consistent with TAPOs. For TAPOs occurring because of MET-TKI, the drug can be continued under careful observation even if GGOs appear.

Epipericardial fat necrosis in a patient with sudden chest pain.

Epipericardial fat necrosis (EFN) may be considered in the differential diagnosis of chest pain. Clinicians should be kept in mind that EFN is self-limiting and is often followed up with imaging.

Negative pressure pulmonary edema in a patient with COVID-19.

Negative pressure pulmonary edema (NPPE) should be considered in the differential diagnosis from an episode of asphyxia, and even if NPPE is diagnosed, the possibility of COVID-19 should be kept in mind under coronavirus pandemic conditions.

A retrospective analysis of revision framework surgeries for unilateral vocal fold paralysis / Análise retrospectiva das cirurgias de revisão do arcabouço laríngeo para paralisia unilateral de prega vocal

Abstract Introduction Revision framework surgeries might be required for unilateral vocal fold paralyses. However, outcomes and indications of revision surgeries have not been adequately documented. For a better understanding of indications for the procedure and to help in achieving better vocal outcomes, we performed a retrospective chart review of patients who underwent revision framework surgeries for unilateral vocal fold paralysis. Objectives This study aimed to present clinical features of patients who underwent revision framework surgeries for the treatment of unilateral vocal fold paralysis. Methods Of the 149 framework surgeries performed between October 2004 and October 2019, 21 revision framework surgeries were performed in 19 patients. Self-assessments by patients using the voice handicap index-10 questionnaire, and objective aerodynamic and acoustic assessments performed pre- and post-operatively were analyzed using the Wilcoxon's signed-rank test for paired comparisons. Results Undercorrection was indicated as reasons for revision surgeries in all cases. The revision techniques included type I thyroplasty, type IV thyroplasty, and arytenoid adduction, and revision surgeries were completed without any severe complication in all cases. Pre- and post-operative voice handicap index-10 scores were obtained in 12 cases, and other parameters were evaluated in 18 cases. Significant improvements were observed in voice handicap index-10 scores, maximum phonation time, mean flow rate, Current/Direct Current ratio, and pitch perturbation quotient. Conclusion Undercorrection was observed in all patients who underwent revision framework surgeries for unilateral vocal fold paralysis, and the initial assessment and planning are thought to be important in order to avoid revision surgeries. Revision surgeries were performed safely in all cases, and significantly improved vocal outcomes were observed, even after multiple procedures. Revision surgery should be considered for patients with unsatisfactory vocal functions after primary framework surgeries for unilateral vocal fold paralysis.

Resumo Introdução As cirurgias de revisão do arcabouço laríngeo podem ser necessárias em casos de paralisia unilateral de prega vocal. Entretanto, os resultados e as indicações das cirurgias de revisão não têm sido documentados de forma adequada. Para melhor compreensão das indicações do procedimento e para auxiliar na obtenção de melhores resultados vocais, fizemos uma revisão retrospectiva dos prontuários de pacientes submetidos a cirurgias de revisão do arcabouço laríngeo em paralisia unilateral de prega vocal. Objetivos Apresentar as características clínicas de pacientes submetidos a cirurgias de revisão do arcabouço laríngeo para tratamento de paralisia unilateral de prega vocal. Método Das 149 cirurgias de revisão do arcabouço laríngeo feitas entre outubro de 2004 e outubro de 2019, 21 cirurgias de revisão do arcabouço laríngeo foram feitas em 19 pacientes. As autoavaliações feitas pelos pacientes com o questionário voice handicap index‐10 e avaliações aerodinâmicas e acústicas objetivas feitas no pré e pós‐operatório foram analisadas com o teste de postos sinalizados de Wilcoxon para comparações pareadas. Resultados A hipocorreção foi apontada como o motivo das cirurgias de revisão em todos os casos. As técnicas de revisão incluíram tireoplastia tipo I, tireoplastia tipo IV e adução de aritenoide. As cirurgias de revisão foram feitas sem qualquer complicação grave em todos os casos. Os escores do questionário voice handicap index‐10 pré e pós‐operatórios foram obtidos em 12 casos e outros parâmetros foram avaliados em 18 casos. Melhorias significativas foram observadas nos escores do questionário, no tempo máximo de fonação, taxa de fluxo médio, relação antes/depois e no quociente de perturbação do pitch. Conclusão Hipocorreção foi observada em todos os pacientes submetidos a cirurgias de revisão do arcabouço laríngeo para paralisia unilateral de prega vocal e a avaliação inicial e o planejamento são considerados importantes para evitar cirurgias de revisão. As cirurgias de revisão foram feitas com segurança em todos os casos e melhoria significativa dos resultados vocais foi observada mesmo após múltiplos procedimentos. A cirurgia de revisão deve ser considerada para pacientes com funções vocais insatisfatórias após cirurgia primária do arcabouço laríngeo para paralisia unilateral de prega vocal.

Clustering out-of-hospital cardiac arrest patients with non-shockable rhythm by machine learning latent class analysis.

Aim: We aimed to identify subphenotypes among patients with out-of-hospital cardiac arrest (OHCA) with initial non-shockable rhythm by applying machine learning latent class analysis and examining the associations between subphenotypes and neurological outcomes. Methods: This study was a retrospective analysis within a multi-institutional prospective observational cohort study of OHCA patients in Osaka, Japan (the CRITICAL study). The data of adult OHCA patients with medical causes and initial non-shockable rhythm presenting with OHCA between 2012 and 2016 were included in machine learning latent class analysis models, which identified subphenotypes, and patients who presented in 2017 were included in a dataset validating the subphenotypes. We investigated associations between subphenotypes and 30-day neurological outcomes. Results: Among the 12,594 patients in the CRITICAL study database, 4,849 were included in the dataset used to classify subphenotypes (median age: 75 years, 60.2% male), and 1,465 were included in the validation dataset (median age: 76 years, 59.0% male). Latent class analysis identified four subphenotypes. Odds ratios and 95% confidence intervals for a favorable 30-day neurological outcome among patients with these subphenotypes, using group 4 for comparison, were as follows; group 1, 0.01 (0.001-0.046); group 2, 0.097 (0.051-0.171); and group 3, 0.175 (0.073-0.358). Associations between subphenotypes and 30-day neurological outcomes were validated using the validation dataset. Conclusion: We identified four subphenotypes of OHCA patients with initial non-shockable rhythm. These patient subgroups presented with different characteristics associated with 30-day survival and neurological outcomes.

Association between initial body temperature on hospital arrival and neurological outcome among patients with out-of-hospital cardiac arrest: a multicenter cohort study (the CRITICAL study in Osaka, Japan).

BACKGROUND: The association between spontaneous initial body temperature on hospital arrival and neurological outcomes has not been sufficiently studied in patients after out-of-hospital cardiac arrest (OHCA). METHODS: From the prospective database of the Comprehensive Registry of Intensive Care for OHCA Survival (CRITICAL) study in Osaka, Japan, we enrolled all patients with OHCA of medical origin aged > 18 years for whom resuscitation was attempted and who were transported to participating hospitals between 2012 and 2019. We excluded patients who were not witnessed by bystanders and treated by a doctor car or helicopter, which is a car/helicopter with a physician. The patients were categorized into three groups according to their temperature on hospital arrival: ≤35.9 °C, 36.0-36.9 °C (normothermia), and ≥ 37.0 °C. The primary outcome was 1-month survival, with a cerebral performance category of 1 or 2. Multivariable logistic regression analyses were performed to evaluate the association between temperature and outcomes (normothermia was used as the reference). We also assessed this association using cubic spline regression analysis. RESULTS: Of the 18,379 patients in our database, 5014 witnessed adult OHCA patients of medical origin from 16 hospitals were included. When analyzing 3318 patients, OHCA patients with an initial body temperature of ≥37.0 °C upon hospital arrival were associated with decreased favorable neurological outcomes (6.6% [19/286] odds ratio, 0.51; 95% confidence interval, 0.27-0.95) compared to patients with normothermia (16.4% [180/1100]), whereas those with an initial body temperature of ≤35.9 °C were not associated with decreased favorable neurological outcomes (11.1% [214/1932]; odds ratio, 0.78; 95% confidence interval, 0.56-1.07). The cubic regression splines demonstrated that a higher body temperature on arrival was associated with decreased favorable neurological outcomes, and a lower body temperature was not associated with decreased favorable neurological outcomes. CONCLUSIONS: In adult patients with OHCA of medical origin, a higher body temperature on arrival was associated with decreased favorable neurologic outcomes.

Early prognostic impact of serum sodium level among out-of-hospital cardiac arrest patients: a nationwide multicentre observational study in Japan (the JAAM-OHCA registry).

Dysnatremia is an electrolytic disorder commonly associated with mortality in various diseases. However, little is known about dysnatremia in out-of-hospital cardiac arrest (OHCA) cases. Here, we investigated the association between serum sodium level on hospital arrival and neurological outcomes after OHCA. This nationwide hospital-based observational study (The Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest registry) enrolled patients with OHCA between 2014 and 2017. We included adult patients aged ≥ 18 years with non-traumatic OHCA who achieved return of spontaneous circulation (ROSC) and whose serum sodium level on hospital arrival was available. Based on the serum sodium level, patients were divided into three levels: hyponatremia (Na < 135 mEq/L), normal sodium level (Na ≥ 135 or ≤ 145 mEq/L), and hypernatremia (Na > 145 mEq/L). The primary outcome was 1-month survival with favourable neurological outcomes. Altogether, 34 754 patients with OHCA were documented, and 5160 patients with non-traumatic OHCA and who achieved ROSC were eligible for our analyses. The proportion of favourable neurological outcomes was highest in patients with normal sodium levels at 17.6% (677/3854), followed by patients with hyponatremia at 8.2% (57/696) and patients with hypernatremia at 5.7% (35/610). Moreover, hyponatremia and hypernatremia were associated with a decreased probability of favourable neurological outcomes compared with normal sodium level (vs. hyponatremia, adjusted odds ratio [AOR] 0.97, 95% confidence interval [CI] 0.95-0.99; vs. hypernatremia, AOR 0.96, 95% CI 0.94-0.98). Hypo- and hypernatremia on hospital arrival were associated with a decreased probability of favourable neurological outcomes in patients with non-traumatic OHCA who achieved ROSC.

Transplantation of a human induced pluripotent stem cell-derived airway epithelial cell sheet into the middle ear of rats.

INTRODUCTION: Early postoperative regeneration of the middle ear mucosa is essential for the prevention of postoperative refractory otitis media and recurrent cholesteatoma. As a means for intractable otitis media management, we focused on human induced pluripotent stem cell (hiPSC)-derived airway epithelial cells (AECs), which have been used in upper airway mucosal regeneration and transplantation therapy. In this study, we transplanted hiPSC-derived AECs into the middle ear of immunodeficient rats. METHODS: Following the preparation of AEC sheets from hiPSCs, the bilateral middle ear mucosa of X-linked severe combined immunodeficient rats was scraped, and the AEC sheets were transplanted in the ears unilaterally. RESULTS: Human nuclear antigen (HNA)-positive ciliated cells were observed on the transplanted side of the middle ear cavity surface in three of six rats in the 1-week postoperative group and in three of eight rats in the 2-week postoperative group. No HNA-positive cells were found on the control side. The percentage of HNA-positive ciliated cells in the transplanted areas increased in the 2-week postoperative group compared with the 1-week group, suggesting survival of hiPSC-derived AECs. Additionally, HNA-positive ciliated cells were mainly located at sites where the original ciliated cells were localized. Immunohistochemical analysis showed that the transplanted AECs contained cytokeratin 5- and mucin 5AC-positive cells, indicating that both basal cells and goblet cells had regenerated within the middle ear cavity. CONCLUSIONS: The results of this study are an important first step in the establishment of a novel transplantation therapy for chronic otitis media.